Closed end connector



Aug. 20, 1957 H. o. WOOLLEY, JR 2,303,695

. CLOSED END CONNECTOR Filed May 3, 1951 TIE'AL' A TTORNE Y5 I ite 2,893,695 Patented Aug. 20, 1957 CLOSED END CONNECTOR Harold D. Woolley, Jr., Lemoyne, Pa., assignor to AMP Incorporated, a corporation of New Jersey Application May 3, 1951, Serial No. 224,370

1 Claim. (Cl. 174-87) This invention relates to insulated electrical connectors of the type adapted for pressure application on a wire to make an electrical connection therewith. More particularly this invention relates to closed-end insulation for conducting members and a method for closing the insulation about one end thereof.

In connectors of the type adapted to permanently join two or more wires or the like, it is sometimes desired to insulate the connector before pressure-forming and it is in addition sometimes desirable to seal the insulation over one end.

Heretofore when making closed-end insulating sleeves for connectors and other conducting elements, it has been the practice to seal the end of the tough malleable plastic sleeve after application onto the conducting element by heating and spinning the sleeve against a tool so as to work some of the material of the sleeve over the end.

It is a primary object of the present invention to provide a closed-end insulating sleeve that can be more easily and quickly formed, and is certainly and perfectly sealed.

It is another object to provide an end closure that will not expand the circumference of the insulating sleeve.

It is a still further object to provide an end closure requiring only a very short end to seal the insulating sleeve.

Another object is to provide for a long leakage path through the closed end of the insulation in the event of any hidden defect in the closure; so that the insulation will be fully effective notwithstanding such defect.

Other and further objects will be in part obvious and in part pointed out as the specification proceeds.

In the drawings:

Figure 1 is a perspective view of a connector according to the present invention;

Figure 2 is a section on line 2--2 of Figure 1;

Figure 3 is an end view of the closing jaws and a sleeve to be closed;

Figure 4 is a view similar to Figure 3 showing the jaws in full compressing position;

Figure 5 is a side view of the die used in Figures 3 and 4;

Figure 6 is a perspective view of a connector similar to Figure 1 after crimping;

Figure 7 is a perspective view of another embodiment of the present invention; and

Figure 8 is a perspective view of a still further embodiment of the present invention showing fragmentary portions of the dies for forming the end closure.

Referring to Figures 1 and 2, a ferrule portion 10 is surrounded by an insulating sleeve 12 which extends substantially beyond both ends of the ferrule portionone end 14 of which forms the mouth to receive, embrace and support the insulation of the wires to be crimped (Figures 6 and 7) and the other end to be closed .over and seal the opposite end of the connector. If desired,

the metal ferrule 10 may be located on the outside of the plastic instead of inside; or it may be omitted altogether if the plastic is sufficiently rigid and malleable.

The insulating sleeve 12 is a tough malleable thermoplastic capable at room temperature of transmitting pressure sufficient to cold flow the metal of the ferrule without destroying the insulating properties of the plastic, and also capable of being formed itself by such pres-- sure. Among such plastics, for example, are the slightly plasticized vinyl chlorides often referred to as rigid vinyl chloride plastics, which will ordinarily have a few percent of vinyl acetate as plasticizer-copolymer. Others are molding nylon and v-inylidene chloride (sold commercially as Saran).

Referring to Figure 3, four die jaws 16 are radially disposed at substantially equal intervals about the axis 18 of the sleeve when positioned for closing of its end. Each jaw face has an included angle of about a lower beveled face 22, as shown in Figure 5, and corners 17 rounded to a small radius.

In one form of the invention the insulating sleeve, after assembly on the ferrule, is gently heated until the sleeve is rendered capable of molding without substantial elastic memory and is then positioned so the heated end is substantially centered on the axis 18 and extends only a short distance into the space between the surfaces 24 of the end-closing dies (Figure 3). The jaws are then closed radially toward axis 18 driving adjacent portions of the sleeve circumference together until the opposing faces of .the adjacent portions meet and cohere to seal completely the end of the connector (Figure 4). Since the plastic was heated and softened it may be easily shaped to the form and thickness desired and adjacent portions will readily cohere. The dies are then Withdrawn leaving four radially disposed fins 26, as the remnants of the folds first formed, closing the end of the insulating sleeve with the material driven inward from the sleeve by the dies 16 and extruded from between the surfaces 24 as the dies are closed together..

Alternatively, the assembled ferrule and sleeve is centered between .the die jaws which in their expanded or rest position are maintained at an elevated temperature, of about 400 F for example by gas flames (not shown). The heated dies are forced inwardly against the cold insulating sleeve, which is softened by the heat of the dies, until adjacent portions of the circumference are folded and flowed together to close the end of the insulating sleeve. When the dies are again withdrawn the four radial fins are left closing the sleeve.

The wires to be connected are inserted through the open end 14 into the ferrule 10 and the connector crimped forging the ferrule portion onto the wires in any of the several ways well known to the art (Figures 6 and 7), while the end of the plastic sleeve overlying the wire insulation may be crimped also to tightly embrace and support the wire and if required, to seal the connection.

Thus a simple, positive and tightly sealed end closure for an insulating sleeve can be easily formed.

Referring to Figure 7, the assembled ferrule and sleeve is inserted in a five die assembly, similar to the four die assembly described above in which each die jaw has an included angle of approximately 72, resulting in a five fin end closure.

In general any desired number of fins may be formed, but it should be noted that the parts of the plastic sleeve which are drawn toward the center form a roof or dome which is reinforced by the fins and the material extruded down into the dome therefrom. A better reinforced structure is attained if these reinforcements are distributed at less than 180 intervals. Moreover with only two in dents of approximately 180, the flattening of the sleeve tends to give an end closure which has a greater diameter than the sleeve itself, as shown in Figure 8. If this is objectionable, the dies may be made to surround the end while it is being flattened and extruded and thus confine the extrusion to a direction parallel to the axis, but with more than three indents, this is unnecessary.

This four fin closure combined with a confined crimp, e. g. as shown in Figure 6 and as described in detail in a copending application to Holtzapple, Serial No. 73,946, filed February 1, 1949, produces a closed end insulating sleeve for a connection that does not have a diameter greater than the diameter of the insulating sleeve tubing which in some installations is a highly desirable characteristic.

While there are given above certain specific examples of this invention and its application in practical use and also certain modifications and alternatives, it should be understood that these are not intended to beexhaustive or to be limiting of the invention. On the contrary, these illustrations and the explanations herein are given in order to acquaint others skilled in the art with this invention and the principles thereof and a suitable manner of its application in practical use, so that others skilled in the art may be enabled to modify the invention and to adapt it and apply it in numerous forms, each as may be best suited to the requirement of a particular use.

I claim:

A connector for electrically joining a plurality of coneach fin composed of a sector of the sleeve, said fins forming a reenforcing end closure and extending longitudinally a substantial distance from said dome.

References Cited in the file of this patent UNITED STATES PATENTS 1,719,405 Townsend July 2, 1929 1,883,736 Cotterman Oct. 18, 1932 2,160,313 Norres May 30, 1939 2,338,524 McCabe Jan. 4, 1944 2,377,533 Waters June 5, 1945 2,431,871 Huyett Dec. 2, 1947 2,526,277 Rogofi Oct. 17, 1950 2,543,696 Krueger Feb. 27, 1951 2,740,101 Betts Mar. 27, 1956 FOREIGN PATENTS 492,397 Great Britain Sept. 20, 1938 

